Linear stapling device with vertically movable knife

ABSTRACT

A surgical stapling device includes a tool assembly having an actuation sled assembly that includes an actuation sled and a knife movably supported on the actuation sled. The tool assembly includes structure for moving the knife in relation to the actuation sled between extended and retracted positions in response to movement of the actuation sled through a staple cartridge of the tool assembly. Movement of the knife moves a cutting edge of the knife in relation to the actuation sled within a tissue gap defined by the tool assembly to impart a degree of vertical motion to the cutting edge of the knife. This enables the tool assembly to leverage micro-serrations on the cutting edge of the knife to enhance cutting efficiency of the knife.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 16/529,974 filed Aug. 2, 2019, the entire disclosure of which is incorporated by reference herein.

FIELD

This technology is generally related to surgical stapling devices and, more particularly, to surgical stapling devices that include a tool assembly including a knife blade that is movable within a tissue gap of the tool assembly.

BACKGROUND

Surgical stapling devices for simultaneously cutting and stapling tissue are known in the art and are commonly used during surgical procedures to reduce the time required to perform the surgical procedure and to facilitate endoscopic access to a surgical site. Performing a surgical procedure endoscopically reduces the amount of trauma inflicted on a patient during a surgical procedure to minimize patient discomfort and reduce patient recovery times.

Typically, endoscopic stapling devices include a tool assembly having a first jaw, and a second jaw that can pivot in relation to the first jaw between an open or spaced position and a closed or clamped position. One of the first and second jaws supports a cartridge assembly that includes a plurality of staples and the other of the first and second jaws supports an anvil assembly that includes an anvil having staple deforming pockets that receive and deform legs of the staples when the staples are ejected from the staple cartridge.

In known devices, each of the first and second jaws defines a knife slot that receives a knife blade that extends between the first and second jaws of the tool assembly. The knife blade is configured to move through the tool assembly to cut tissue clamped between the jaws as the staples are formed in the tissue. Typically, the direction of movement on the knife blade applies a horizontal force on the tissue which may lead to tissue accumulation and slippage during staple formation. This may have a negative impact on staple formation.

SUMMARY

The techniques of this disclosure generally relate to surgical stapling devices, and more particularly, to surgical stapling devices that include a knife for transecting tissue. The disclosed surgical stapling devices include a tool assembly having an actuation sled assembly that includes an actuation sled and a knife that is movably supported on the actuation sled. The tool assembly includes structure to facilitate movement of the knife in relation to the actuation sled between extended and retracted positions in response to movement of the actuation sled through a staple cartridge of the tool assembly. Movement of the knife moves a cutting edge of the knife in relation to the actuation sled within a tissue gap defined by the tool assembly to impart a degree of vertical motion to the cutting edge of the knife. This enables the tool assembly to leverage micro-serrations on the cutting edge to enhance cutting efficiency of the knife.

In one aspect of the disclosure, a tool assembly for a surgical stapling device includes a first jaw and a second jaw. The first jaw supports an anvil and the second jaw supports a cartridge assembly. The cartridge assembly includes a staple cartridge defining a plurality of staple pockets, a staple positioned within each of the staple pockets, and an actuation sled assembly. The first and second jaws are movable in relation to each other between an open position and a clamped position in which the staple cartridge is in juxtaposed alignment with the anvil to define a tissue gap. The actuation sled assembly is movable horizontally within the staple cartridge from a retracted position to an advanced position to eject the staples from the staple pockets of the staple cartridge. The actuation sled assembly includes an actuation sled and a knife movable with the actuation sled. The knife defines a cutting edge that extends across the tissue gap when the first and second jaws are in the clamped position. The knife is movable along an axis having a vertical component between extended and retracted positions in relation to the actuation sled in response to horizontal movement of the actuation sled within the staple cartridge to move the cutting edge in relation to the actuation sled within the tissue gap.

In another aspect of the disclosure, a surgical stapling device includes an elongate body having a proximal portion and a distal portion, and a disposable loading unit including a proximal body portion and a tool assembly. The proximal body portion of the disposable loading unit is adapted to be releasably coupled to the distal portion of the elongate body and the tool assembly is supported on the proximal body portion. The tool assembly includes a first jaw supporting an anvil and a second jaw supporting a cartridge assembly. The cartridge assembly includes a staple cartridge defining a plurality of staple pockets, a staple positioned within each of the staple pockets, and an actuation sled assembly that is movable horizontally within the staple cartridge from a retracted position to an advanced position to eject the staples from the staple pockets of the staple cartridge. The first and second jaws are movable in relation to each other between an open position and a clamped position in which the staple cartridge is in juxtaposed alignment with the anvil to define a tissue gap. The actuation sled assembly includes an actuation sled and a knife movable with the actuation sled. The knife defines a cutting edge that extends across the tissue gap when the first and second jaws are in the clamped position. The knife is movable along an axis having a vertical component between extended and retracted positions in relation to the actuation sled in response to horizontal movement of the actuation sled within the staple cartridge to move the cutting edge in relation to the actuation sled within the tissue gap.

In aspects of the disclosure, the actuation sled includes a central body portion that defines a cavity and a plurality of angled cam portions that are positioned on each side of the central body portion.

In some aspects of the disclosure, the knife is movably supported on the actuation sled within the cavity of the central body portion.

In certain aspects of the disclosure, the central body portion of the actuation sled includes side walls that define the cavity and the knife includes a lower portion that is received within the cavity and defines an elongate slot,

In aspects of the disclosure, the tool assembly further includes a guide member that extends between the side walls of the central body portion through the elongate slot in the knife. The guide member is configured to allow reciprocating movement of the knife between the retracted and extended positions.

In some aspects of the disclosure, the guide member includes first and second pins that are positioned within the elongate slot of the knife to limit the knife to linear movement.

In certain aspects of the disclosure, the anvil includes a surface having a wave-like surface and the knife is movable along the wave-like surface to move the knife between the extended and retracted positions.

In aspects of the disclosure, a biasing member is positioned to urge the knife towards the extended position.

In some aspects of the disclosure, the knife is pivotably supported on the actuation sled within the cavity about a pivot member.

In certain aspects of the disclosure, the cavity includes a longitudinal cavity and a transverse cavity and the knife is pivotably supported within the longitudinal cavity and includes an extension that is positioned within the transverse cavity.

In aspects of the disclosure, the tool assembly further includes a rotatable cam that is positioned within the transverse cavity to engage the extension of the knife to move the knife between the extended and retracted positions.

In some aspects of the disclosure, a stationary rod having a thread is supported in the staple cartridge, and the cam defines a threaded bore that receives the stationary rod such that movement of the actuation sled assembly within the staple cartridge causes the cam to rotate within the transverse cavity.

The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

Various aspects and features of the disclosure are described with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views and:

FIG. 1 is a side perspective view of an exemplary aspect of the disclosed stapling device including a tool assembly in a clamped position;

FIG. 2 is an exploded side perspective view of the tool assembly of the stapling device shown in FIG. 1 ;

FIG. 3 is an enlarged view of the indicated area of detail shown in FIG. 2 ;

FIG. 4 is a cross-sectional view taken along section line 4-4 of FIG. 3 ;

FIG. 5 is an exploded side perspective view of an actuation sled assembly of the tool assembly of the stapling device shown in FIG. 1 ;

FIG. 6 is a cross-sectional view taken along section line 6-6 of FIG. 1 ;

FIG. 7 is an enlarged view of the indicated area of detail shown in FIG. 6 ;

FIG. 8 is an enlarged view of the indicated area of detail shown in FIG. 7 as the actuation sled assembly is advanced within the tool assembly;

FIG. 9 is a side schematic view of a distal portion of another exemplary aspect of a tool assembly of the disclosed stapling device shown in FIG. 1 ;

FIG. 9A is a side perspective view of an actuation sled assembly and stationary rod of the tool assembly shown in FIG. 9 ;

FIG. 10 is a side view of a cam of an actuation sled assembly of the tool assembly of the stapling device shown in FIG. 9 ; and

FIG. 11 is a side schematic view of the distal portion of the tool assembly shown in FIG. 10 as the actuation sled assembly is advanced through the tool assembly.

DETAILED DESCRIPTION

This disclosure is directed to a surgical stapling device that includes a tool assembly defining a longitudinal axis and having an actuation sled assembly including an actuation sled and a knife. The knife is movable in relation to the actuation sled within knife slots defined by jaws of the tool assembly to cut tissue. In aspects of the disclosure, movement of the actuation sled horizontally through jaws of the tool assembly imparts a degree of vertical motion to the knife within the knife slots. In some aspects of the disclosure, engagement of the knife with one of the jaws imparts a degree of vertical movement to the knife within the knife slots. In other aspects of the disclosure, a cam member that is driven by a drive screw imparts a degree of vertical movement to the knife within the knife slots.

The disclosed stapling device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that the aspects of the disclosure are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure. In addition, directional terms such as horizontal, vertical, distal, proximal, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure.

In this description, the term “proximal” is used generally to refer to that portion of the device that is closer to a clinician, while the term “distal” is used generally to refer to that portion of the device that is farther from the clinician. In addition, the term “endoscopic” is used generally used to refer to endoscopic, laparoscopic, arthroscopic, and/or any other minimally invasive procedure conducted through small diameter incision or cannula. Further, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel.

FIGS. 1-8 illustrate an exemplary aspect of the disclosed stapling device shown as generally as stapling device 10. Stapling device 10 as illustrated in FIG. 1 includes a powered handle assembly 12, an elongate body 14, and a tool assembly 16. The elongate body 14 defines a longitudinal axis “X” and includes a proximal portion 14 a supported on the handle assembly 12 and a distal portion 14 b that supports the tool assembly 16. In some aspects of the disclosure, the tool assembly 16 forms part of a disposable loading unit 18 that includes a proximal body portion 18 a that is adapted to be releasably coupled to the distal portion 14 b of the elongate body 14 of the stapling device 10. In aspects of the disclosure, the proximal body portion 18 a includes a distal portion that supports the tool assembly 16. In alternate aspects of the disclosure, the tool assembly 16 is fixedly secured to the distal portion of the elongate body 14.

FIG. 1 illustrates the handle assembly 12 of the stapling device 10 which includes a stationary handle 20 and actuation buttons 22 that can be depressed to actuate the tool assembly 16, e.g., approximate the tool assembly 16, articulate the tool assembly 16, fire staples, etc. . . . . In aspects of the disclosure, batteries (not shown) are supported in the stationary handle 20 to power the handle assembly 12. It is envisioned that the stapling device 10 need not be powered but can also include a manually powered handle assembly such as described in U.S. Pat. No. 5,865,361 (“the '361 patent”).

FIG. 2 illustrates the tool assembly 16 which includes a first jaw 30, a second jaw 32, and a drive assembly 34. In aspects of the disclosure, the first jaw 30 supports a cartridge assembly 30 a and the second jaw 32 supports an anvil 32 a. The first and second jaws 30, 32 are secured together with pivot members 36 such that the tool assembly 16 is pivotable between open and clamped positions. In the clamped position, the cartridge assembly 30 a and the anvil 32 a are positioned in juxtaposed alignment and define a tissue gap “G” (FIG. 6 ). In aspects of the disclosure, the first jaw 30 can pivot about the pivot member 36 in relation to the second jaw 32 and the elongate body 14, and the second jaw 32 can be stationary in relation to the elongate body 14. In other aspects of the disclosure, the second jaw 32 can pivot about the pivot member 36 in relation to the first jaw 30 and the elongate body 14, and the elongate body 30 can be stationary in relation to the elongate body 14.

The first jaw 30 includes a channel 40 that supports the cartridge assembly 30 a. The cartridge assembly 30 a includes a staple cartridge 42 that is received within the channel 40, a plurality of staples 44 a, a plurality of pushers 44 b, and an actuation sled assembly 48. In aspects of the disclosure, the staple cartridge 42 is removable from the channel 40 to allow for replacement of spent or used staple cartridges 42 to facilitate reuse of the stapling device 10. The staple cartridge 42 defines a plurality of staple pockets 42 a. Each of the staple pockets 42 a receives one of the plurality of staples 44 a and is associated with one of the plurality of pushers 44 b. Each of the pushers 44 b supports at least one of the plurality of staples 44 a within a respective staple pocket 42 a. The channel 40 and the staple cartridge 42 each define a longitudinal slot 45 a, 45 b (FIG. 2 ), respectively. The longitudinal slot 45 a in the channel 40 is positioned to facilitate passage of a working member 52 of the drive assembly 34 as described below. The longitudinal slot 45 b of the staple cartridge 42 facilitates passage of a knife 72 of an actuation sled assembly 48 as described below. The channel 40 also includes an outer surface 49 that defines a longitudinal recess 49 a (FIG. 6 ).

The drive assembly 34 includes a flexible drive beam 50 and a working member 52 that is secured to a distal portion of a flexible drive beam 50. The working member 52 includes an upper beam 54, a lower beam 56, and a vertical strut 58 that extends between and supports the upper and lower beams 54, 56. The vertical strut 58 includes a blunt distally facing surface 60 (FIG. 2 ). The flexible drive beam 50 includes a proximal portion that supports a connector 62 that is adapted to be coupled to a drive member (not shown) included in the elongate body 14 of the stapling device 10.

The anvil 32 a defines a knife slot 66 (FIG. 6 ) and defines a longitudinal channel 68 within the first jaw 32 that receives the upper beam 54 of the working member 50 of the drive assembly 34. The vertical strut 58 extends from the upper beam 54 through the knife slot 66 of the anvil 32 a and through the knife slots 45 a, 45 b of the channel 40 and the staple cartridge 42, respectively, such that the lower beam 56 is received within the longitudinal recess of the 49 of the channel 40. When the drive assembly 34 is advanced to advance the working member 50 through the tool assembly 16, the upper and lower beams 54, 56, respectively, engage surfaces of the first and second jaws 30 and 32 to define the maximum tissue gap “G” (FIG. 6 ) between the staple cartridge 42 and the anvil 32 a. For a more detailed description of the cartridge assembly 30 a, the drive assembly 34, and the anvil 32 a, see the '361 patent.

FIGS. 2-5 illustrate the actuation sled assembly 48 which includes an actuation sled 70, a knife 72, and a biasing member 74. The actuation sled 70 includes a central body portion 76 that defines a cavity 78 and a plurality of angled cam surfaces 80 that are positioned on each side of the central body portion 76. The cavity 78 extends longitudinally within the body portion 76 of the actuation sled 70. The angled cam surfaces 80 are positioned to engage the pushers 44 a (FIG. 2 ) positioned within the staple pockets 42 a when the actuation sled assembly 48 is driven through the staple cartridge 42 to eject the staples 44 a from the staple cartridge 42 as known in the art. No further description of the interaction between the actuation sled 70 and the pushers 44 a (FIG. 2 ) is included in this specification.

The knife 72 includes a body 82 defining a longitudinal axis “Y” (FIG. 4 ) and having a cutting edge 84 and an elongate slot 86. The body 82 includes a lower portion 82 a that is received within the cavity 78 of the body portion 76 of the actuation sled 70 and an upper portion 82 b that projects outwardly of the cavity 78. The central body portion 76 includes spaced side walls 92 that define the cavity 78. The spaced side walls 92 support at least one guide member 94 that extends across cavity 78 and through the elongate slot 86 of the body 82 of the knife 72. The guide member 94 is configured and dimensioned to allow the knife 72 to move linearly along the longitudinal axis “Y” (FIG. 4 ) of the knife 72 between a first retracted position (FIG. 8 ) and a second extended position (FIG. 7 ). In aspects of the disclosure, the guide member 94 includes a pair of pins (FIG. 5 ) that extend through openings 96 in the side walls 92 of the body portion 76 of the actuation sled 70. Alternately, the guide member or members 94 may assume a variety of different configurations which allow the knife member 72 to reciprocate between its extended and retracted positions.

The biasing member 74 is secured within the cavity 78 of the central body portion 76 of the actuation sled 70 in a position to urge the knife 72 towards its extended position (FIG. 4 ). In aspects of the disclosure, the biasing member 74 includes a leaf spring 98 that is secured to a base wall 100 of the actuation sled 70 that defines the cavity 78 of the actuation sled 70 by rivets 102. Alternately, other biasing members may be used to urge the knife 72 towards its extended position and other fastening techniques can be used to secure the biasing member 74 within the cavity 78 of the body 76 of the actuation sled 70.

FIGS. 6 and 7 illustrate the tool assembly 16 in a clamped, pre-fired position with the staple cartridge 42 positioned in juxtaposed alignment with the anvil 32 a to define the tissue gap “G” (FIG. 6 ). In this position, the knife 72 extends from within the cavity 78 of the actuation sled 70, through the knife slots 45 b and 66 of the staple cartridge 42 and anvil 32 a, respectively, into engagement with an inner surface 110 of the first jaw 32. In aspects of the disclosure, the inner surface 110 of the first jaw 32 has a wave like configuration that is configured to move or reciprocate the knife 72 along the Y axis between its retracted and extended positions as the actuation sled assembly 48 is moved horizontally within the staple cartridge 42 to cut tissue (not shown) that is clamped between the staple cartridge 42 and the anvil 32 a.

The cutting edge 84 of the knife 72 faces distally and is positioned to reciprocate within the tissue gap “G” as the knife 72 translates through the staple cartridge 42. In aspects of the disclosure, the cutting edge 84 may be substantially parallel to the Y-axis and define an acute angle β with a longitudinal axis “X” (FIG. 7 ) of the tool assembly 16. In aspects of the disclosure, β can be from about thirty (30) degrees to about eighty-five (85) degrees. In some aspects of the disclosure, β can be from about forty (40) degrees to about seventy (70) degrees. Alternately, it is envisioned that other cutting edge orientations may be warranted, e.g., ninety (90) degrees, one hundred five (105) degrees, etc.

FIG. 8 illustrates the working member 52 of the drive assembly 34 as it translates through the staple cartridge 42 and the anvil 32 in the direction indicated by arrows “S”. As the working member 52 moves through the staple cartridge 42, the blunt distal face 60 of the vertical strut 58 of the working member 52 engages the proximal side of the central body portion 76 of the actuation sled assembly 48 to advance the actuation sled assembly 48 through the staple cartridge 42. As the actuation sled assembly 48 moves through the staple cartridge 42, the upper end of the knife 72 engages and moves along the wave-like inner surface 110 of the anvil 32. Contact between the knife 72 and the wave-like inner surface 110 causes the knife 72 to move initially in the direction indicated by arrows “T” against the urging of the biasing member 74 from the extended position to a retracted position. As the knife 72 continues to move along the wave-like inner surface 110 of the anvil 32, the biasing member 74 returns the knife 72 to the extended position such that the knife 72 reciprocates along the axis “Y” of the knife 72 within the gap “G” between the staple cartridge 42 and the anvil 32 a. As illustrated the axis “Y” includes both a horizontal and vertical component as viewed in FIG. 8 . As disclosed above, other knife orientations are envisioned.

FIGS. 9-11 illustrate another exemplary aspect of the disclosed tool assembly for use with a surgical stapling device shown generally as tool assembly 216. The tool assembly 216 is similar to tool assembly 16 (FIG. 1 ) described above and includes a first jaw 230 supporting a cartridge assembly 230 a and a second jaw 232 supporting an anvil 232 a. The cartridge assembly 230 includes a staple cartridge 242, and an actuation sled assembly 248. The cartridge assembly 230 is associated with a drive assembly (not shown), such as drive assembly 34 (FIG. 2 ) to translate the actuation sled assembly 248 through the staple cartridge 242. The first and second jaws 230, 232 are movable in relation to each other between open and clamped positions. In the clamped position (FIG. 9 ), the staple cartridge 242 is positioned in juxtaposed alignment with the anvil 232 a to define a tissue gap “G”. The tool assembly 216 forms part of a stapling device such as stapling device 10 (FIG. 1 ) which can be actuated to advance the drive assembly (not shown) to cause the actuation sled 248 to translate through the staple cartridge 242 to eject staples 44 a (FIG. 2 ) from the staple cartridge 242. The tool assembly 216 will only be described in detail to describe the components that differ from those described above in regard to tool assembly 16.

The tool assembly 216 includes a stationary rod 250 that extends through the staple cartridge 242 centrally along the length of the staple cartridge 242 and includes a thread 252 that spirals about the rod 250. The actuation sled assembly 248 includes an actuation sled 270, a knife 272, a cam 273, and a biasing member 274. FIG. 9A illustrates the actuation sled 270 which includes a central body portion 276 that defines a cavity 278 (FIG. 9A) and a transverse cavity 279, and includes a plurality of angled cam surfaces (not shown) that are positioned on each side of the central body portion 276. The cavity 278 extends longitudinally within the central body portion 276. The angled cam surfaces are substantially similar to the angled cam surfaces 80 (FIG. 2 ) as described above in both configuration and function, and will not be described further detail herein. The transverse cavity 279 communicates with a proximal end of the longitudinal cavity 278 and receives the cam 273. The stationary rod 250 is positioned to one side of the longitudinal cavity 278 and extends through a threaded bore 300 defined in the cam 273.

The knife 272 includes a body 282 having a cutting edge 284. In aspects of the disclosure, the cutting edge 284 faces distally and may have an arcuate shape although other shapes are envisioned linear. The body 282 includes a lower portion 282 a that is received within the longitudinal cavity 278 of the body portion 276 of the actuation sled 270 and an upper portion 282 b that projects outwardly of the longitudinal cavity 278 such that the cutting edge 284 extends across the tissue gap “G” (FIG. 9 ) defined between the staple cartridge 242 and the anvil 232 a. The central body portion 276 includes spaced side walls 292 that define the longitudinal cavity 278. The spaced side walls 292 support a pivot member 294 that extends across longitudinal cavity 278 to pivotably support the knife 272 within the longitudinal cavity 278 such that the knife 272 is rotatable between extended (FIG. 9 ) and retracted (FIG. 11 ) positions. The knife body 282 includes a proximal extension 302 that is positioned within the transverse cavity 279 at a position to engage the cam 273.

FIG. 10 illustrates the cam 273 which includes a lobe portion 306 that is spaced from the threaded bore 300. As described above, the threaded bore 300 of the cam 273 receives the stationary rod 250 such that the thread 252 of the stationary rod 250 is engaged with the threaded bore 300 of the cam 273. When the actuation sled assembly 248 is moved longitudinally within the staple cartridge 242, the cam 273 is moved along the stationary rod 250. As described above, the stationary rod 250 is fixedly positioned within the staple cartridge 242. As such, longitudinal movement of the cam 273 along the stationary rod 250 causes the cam 273 to rotate within the transverse cavity 279 (FIG. 9 ) of the actuation sled 270 as the actuation sled 270 moves longitudinally within the staple cartridge 242.

FIG. 9 illustrates the biasing member 274 of the actuation sled assembly 248 which is positioned to urge the knife 272 to the extended position. In aspects of the disclosure, the biasing member 274 includes a torsion spring that is positioned to urge the knife 272 about the pivot member 294 in the direction of arrow “U” in FIG. 11 towards the extended position. Alternately, other types of biasing mechanisms could be used to urge the knife 272 towards the extended position.

FIG. 11 illustrates the tool assembly 216 as the actuation sled assembly is moved from a retracted position towards an advanced position to fire staples 44 a (FIG. 2 ) from the staple cartridge 242. Although not shown, a drive assembly such as drive assembly 34 including working member 52 (FIG. 2 ) is provided to engage and advance the actuation sled assembly 248 within the staple cartridge 242. As the actuation sled assembly 248 moves within the staple cartridge 242 in response to advancement of the drive assembly 34 (FIG. 2 ) within the staple cartridge 242, the cam 273 moves along the stationary rod 250. As the cam 273 moves along the stationary rod 250, engagement between the thread 252 of the stationary rod 250 and the threaded bore 300 (FIG. 10 ) of the cam 273 causes the cam 273 to rotate within the transverse cavity 279 about the stationary rod 250 in the direction indicated by arrow “V”. As the cam 273 rotates within the transverse cavity 279, the lobe portion 306 of the cam 273 engages the proximal extension 302 of the knife 272 to urge the knife 272 against the urging of the biasing member 274 from the extended position towards the retracted position. When the lobe portion 306 of the cam 273 moves to a position to pivot the knife 272 to the extended position, the lobe portion 306 disengages from the knife 272. When this occurs, the biasing member 274 returns the knife 272 to its retracted position and this cycle repeats itself such that the cutting edge 284 of the knife 272 reciprocates within the tissue gap “G” of the tool assembly 216. It is noted that in both of the extended and retracted positions of the knife 272, the cutting edge 284 of the knife 272 extends entirely across the tissue gap “G”.

It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device. 

What is claimed is:
 1. A tool assembly for a surgical stapling device comprising: a first jaw supporting an anvil; a second jaw supporting a cartridge assembly, the cartridge assembly including a staple cartridge defining a knife slot and a plurality of staple pockets, and a staple positioned within each of the staple pockets, the knife slot having a length, the first and second jaws being movable in relation to each other between an open position and a clamped position in which the staple cartridge is in juxtaposed alignment with the anvil to define a tissue gap; and an actuation sled assembly movable horizontally within the staple cartridge from a retracted position to an advanced position to eject the staples from the staple pockets of the staple cartridge, the actuation sled assembly including an actuation sled and a knife movable with the actuation sled, the knife defining a cutting edge that extends across the tissue gap when the first and second jaws are in the clamped position, wherein the horizontal movement of the actuation sled from the retracted position to the advanced position moves the knife along the length of the knife slot so as to move the cutting edge within the tissue gap; wherein the knife is continuously movable relative to the actuation sled during the horizontal movement of the actuation sled from the retracted position to the advanced position; and wherein the continuous movement of the knife relative to the actuation sled moves the knife along a path having a vertical component and having a plurality of retracted positions and a plurality of extended positions.
 2. The tool assembly of claim 1, wherein the actuation sled includes a central body portion and a plurality of angled cam portions positioned on each side of the central body portion, the central body portion defining a cavity.
 3. The tool assembly of claim 2, wherein the knife is movably supported on the actuation sled within the cavity of the central body portion.
 4. The tool assembly of claim 3, wherein the central body portion of the actuation sled includes side walls that define the cavity and the knife includes a lower portion that is received within the cavity, the lower portion of the knife defining an elongate slot, and the tool assembly further including a guide member that extends between the side walls of the central body portion through the elongate slot in the knife, the guide member being configured to allow reciprocating movement of the knife between retracted and extended positions.
 5. The tool assembly of claim 4, wherein the guide member includes first and second pins, the first and second pins being positioned within the elongate slot of the knife to limit the knife to linear movement.
 6. The tool assembly of claim 5, wherein the anvil includes a surface having a wave-like configuration, the knife being movable along the surface to move the knife between the extended and retracted positions.
 7. The tool assembly of claim 6, further including a biasing member positioned to urge the knife towards one of the extended and retracted positions.
 8. A surgical stapling device comprising: an elongate body having a proximal portion and a distal portion; and a disposable loading unit including a proximal body portion and a tool assembly, the proximal body portion adapted to be releasably coupled to the distal portion of the elongate body, and the tool assembly being supported on the proximal body portion, the tool assembly including: a first jaw supporting an anvil; a second jaw supporting a cartridge assembly, the cartridge assembly including a staple cartridge defining a knife slot and a plurality of staple pockets, and a staple positioned within each of the staple pockets, the knife slot having a length, the first and second jaws being movable in relation to each other between an open position and a clamped position in which the staple cartridge is in juxtaposed alignment with the anvil to define a tissue gap; and an actuation sled assembly movable horizontally within the staple cartridge from a retracted position to an advanced position to eject the staples from the staple pockets of the staple cartridge, the actuation sled assembly including an actuation sled and a knife movable with the actuation sled, the knife defining a cutting edge that extends across the tissue gap when the first and second jaws are in the clamped position, wherein the horizontal movement of the actuation sled from the retracted position to the advanced position moves the knife along the length of the knife slot so as to move the cutting edge within the tissue gap; wherein the knife is continuously movable relative to the actuation sled during the horizontal movement of the actuation sled from the retracted position to the advanced position; and wherein the continuous movement of the knife relative to the actuation sled moves the knife along a path having a vertical component and having a plurality of retracted positions and a plurality of extended positions.
 9. The surgical stapling device of claim 8, wherein the actuation sled includes a central body portion and a plurality of angled cam portions positioned on each side of the central body portion, the central body portion defining a cavity.
 10. The surgical stapling device of claim 9, wherein the knife is movably supported on the actuation sled within the cavity of the central body portion.
 11. The surgical stapling device of claim 10, wherein the central body portion of the actuation sled includes side walls that define the cavity and the knife includes a lower portion that is received within the cavity, the lower portion of the knife defining an elongate slot, and the tool assembly further including a guide member that extends between the side walls of the central body portion through the elongate slot in the knife, the guide member being configured to allow reciprocating movement of the knife between retracted and extended positions.
 12. The surgical stapling device of claim 11, wherein the guide member includes first and second pins, the first and second pins being positioned within the elongate slot of the knife to limit the knife to linear movement.
 13. The surgical stapling device of claim 12, wherein the anvil includes a surface having a wave-like configuration, the knife being movable along the wave-like surface to move the knife between the extended and retracted positions.
 14. The surgical stapling device of claim 13, further including a biasing member positioned to urge the knife towards one of the extended and retracted positions. 